JP7216646B2 - Grating structure for X-ray imaging, X-ray imaging system with said grating structure, and method for manufacturing said grating structure - Google Patents

Description

The present invention relates to an X-ray imaging grid, an X-ray imaging system and a method for manufacturing an X-ray imaging grid.

In X-ray imaging, gratings are used, for example, for differential phase-contrast imaging or dark-field imaging. The grating provides a repeating pattern of alternating areas, for example strips of x-ray attenuating material, with areas of low x-ray attenuation. Another application of X-ray gratings is anti-scatter grids. There is a desire for large aspect ratios associated with higher image quality. Gratings with large aspect ratios and thin-walled segments are less mechanically stable and require additional fixation. For example, International Patent Publication No. WO2012/055495A1 describes a resist structure for manufacturing an X-ray optical grating structure.

Therefore, there is a need to provide a grid that aids in stabilization.

The object of the invention is solved by the subject matter of the independent claims. Further embodiments are incorporated in the dependent claims. It should be noted that the below-described aspects of the invention also apply to the X-ray imaging grid, the X-ray imaging system and the method of manufacturing the X-ray imaging grid.

SUMMARY OF THE INVENTION In accordance with the present invention, a grid for X-ray imaging is provided. The grid includes a grid structure having a first plurality of bar members and a second plurality of gaps. The grid further includes securing structures disposed between the bar members to stabilize the grid bar members. The bar members extend lengthwise and heightwise. Further, the bar members are separated from each other in a direction transverse to the height direction by one of the gaps. The gap is arranged with the gap direction parallel to the length direction. The fixed structure includes a plurality of bridging web members provided between adjacent bar members. The web members are longitudinal web members that extend in the gap direction and are provided at an angle to the height direction. A slope is given in the gap direction.

The slanted arrangement of the web members results in less artifacts on the x-ray detector, ie less effect of the slanted web members, as the slanting occurs in and towards the gap. The tilted arrangement also facilitates manufacturing.

The securing structure includes a plurality of bridging web members disposed within the gap and provided between adjacent bar members.

In one embodiment, the bar members provide first grid members and the gaps provide second grid members. The web members provide bridging members connecting adjacent first grid members and the bridging members protrude through, i.e. extend or span across, the second grid members. be That is, the bridging member crosses the second grid member. Accordingly, the second grid members, or gaps, are arranged to provide a corresponding gap (or imaging) function (i.e., provide regions or spaces with different X-ray attenuation or absorption properties than the bar members). including the space between the bar members that are The second grid member, or interstices, also include spaces in which web members are installed, which spaces are arranged to provide a corresponding stabilizing (or mechanical) function.

Thus, the bridging members each occupy a portion of the gap and take up a small portion of the gap.

Thus, the second grid member, or interstices, include bridging members and the resulting net interstitial spaces. The space occupied by the bridging member is also called bridging space or connecting space.

Thus, the first plurality of bar members are interconnected by web members bridging the second plurality of gaps.

The web members provide stabilizing elements for the bar members.

According to one embodiment, the web members and bar members are made from the same material.

In one option, the web members and bar members are made as a unitary structure.

The term "same material" primarily relates to the X-ray attenuation properties of the material. Options use exactly the same material. Another option is to use different materials, but with essentially the same X-ray attenuation properties.

In one embodiment, the web members and bar members are made in one piece, for example by a common manufacturing process.

The interstitial space, ie the resulting net interstitial space, comprises a different material, ie a material different from that of the bar members and bridge members. The materials of the interstitial spaces differ at least with respect to their X-ray attenuation properties.

According to one embodiment, the bar members and web members are made of structural material and an X-ray absorbing material is disposed within the gaps. The structural material absorbs less x-rays than the x-ray absorbing material.

Thus, the first plurality of bar members and web members provide the structural structural component of the lattice structure, ie the structural structure or support structure of the lattice structure. The second plurality of interstices provides a lattice-structured x-ray absorbing feature, ie, a lattice-structured x-ray absorbing structure or an x-ray blocking structure.

"Absorbing material" refers to a material that absorbs most of the emitted X-rays. For example, in X-ray imaging, the unabsorbed X-ray dose is very small. For example, the absorbing material includes lead and/or gold. Absorbent material is provided within the resulting net interstitial space. The gap thus includes a primary portion comprising the absorbent material and a (smaller) secondary portion comprising the structural material of the web member.

Therefore, if the gap is the area between the bar members, the X-ray absorber is arranged in part of the gap. When the term "gap" is used for the resulting net interstitial space, i.e., the space between the bar members minus the space occupied by the web members, the X-ray absorbing material is disposed in the gap. . In one embodiment, the gap (when understood as the net interstitial space) is completely filled with X-ray absorbing material. In another embodiment, the gap (again when understood as the net interstitial space) is partially filled with an X-ray absorbing material. Other portions may be filled with additional material or left empty.

"Structural material" relates to materials that give the grid sufficient rigidity, at least for handling during manufacture and assembly of the grid. For example, structural materials include silicon or other materials suitable for gratings in X-ray imaging. In one embodiment, the structural material provides structural or mechanical stability of the lattice. The structural material provides at least stability such that the absorbent material is securely attached and supported by the bar members and/or web members.

In one embodiment, the bar members and web members are made from the same material. In another embodiment, two different materials are used for the bar members and web members.

According to one embodiment, the grating is an absorbing grating and the grating structure is made such that the gaps are filled with an X-ray absorbing material for X-ray absorption by the gaps. The bar members are arranged to have low x-ray absorption due to radiation x-ray transmission within the bar members.

The x-ray absorbing material in the gap is more x-ray absorbing than the web member.

A web member is provided along the gap in an oblique configuration with respect to the x-ray line of sight. This diagonal structure interrupts the absorbent structure along the gap.

The web members form only a fraction of the gap space in the X-ray line-of-sight direction and as a result the gaps are always more X-ray absorbing than the bar members.

According to one embodiment, the grid is an absorbing grid and the grid structure is made such that the interstices are filled with an X-ray absorbing material for X-ray absorption by the interstices. The bar members are arranged such that there is less X-ray absorption due to transmission of radiation X-rays within the bar members, ie, less absorption due to transmission of X-rays within the bar members.

According to another embodiment, the grating is an absorbing grating, and for X-ray absorption by the bar members, the grating structure is made such that the bar members are made of an X-ray absorbing material. The gap is provided such that the absorption is low due to the transmission of radiation X-rays within the gap, ie due to the transmission of X-rays within the gap.

Optionally, the interstices are less x-ray absorbing than the web segments.

The interstitial space absorbs less x-rays than the web member reaching through the interstices. The web member can be provided by an X-ray absorbing material, for example the same material used for the bar member. Since the web member forms only a small portion of the gap space in the X-ray line of sight, as a result the gap will always absorb less X-rays than the bar member.

The gap may be provided with an X-ray transparent filler or may be provided unfilled. Because the web member is slanted, the attenuation by the web member is more distributed with respect to the radial x-ray direction, thereby improving the x-ray signal.

According to one embodiment, web members are arranged between adjacent bar members such that the web members connect opposing portions of the bar members.

According to another embodiment, in the unassembled state the web members are arranged parallel to each other.

The grating may be bent for focusing during assembly. For example, the grid may be attached to a curved support structure or a curved mounting surface.

Optionally, in the unassembled state, the web member is positioned with respect to the radial direction of the fan-shaped x-ray beam. The web members are arranged at the same oblique angle with respect to the radial direction.

An unassembled state refers to a state in which the grid is not mounted in its final position within the X-ray imaging system.

According to one embodiment, at least one first gap and at least one web segment are provided over the height in the X-ray viewing direction.

In one embodiment, in the unmounted state, the grid is provided as a planar grid and, within the gaps, across the plane of the grid, e.g. , at least one gap and at least one web segment are provided.

According to one embodiment, the web members are arranged to provide continuous x-ray attenuation along the gap in the radial x-ray line-of-sight direction.

This further enhances the X-ray detector signal and reduces the effort for post-processing of the signal.

If X-ray absorption is provided by the gap, a continuous fairly high absorption is provided along the gap. This high absorption is provided by the X-ray absorbing material located within the gap. The material is provided in addition to a web member that is also positioned within the gap. The web member itself provides moderately low attenuation (ie, no or near no x-ray absorption). Furthermore, a continuous moderately low or very low attenuation is provided along the bar member (eg, X-ray transparent, ie, there is negligible X-ray attenuation from the point of view of X-ray imaging).

If the X-ray absorption is provided by the bar members, a continuous fairly high absorption is provided along the bar members. This high absorption is provided by the X-ray absorbing material of the bar members. Furthermore, a continuous moderately low or very low attenuation is provided along the gap (e.g. nearly X-ray transparent, i.e. there is negligible X-ray attenuation from the point of view of X-ray imaging). . Web members are also placed in the gaps, the gaps themselves providing X-ray attenuation by means of materials that provide X-ray absorption, but due to their small contribution in the radial X-ray direction, the web members are rather low provide damping.

According to one embodiment, the web member extends continuously from the upper edge of the bar member to the lower edge of the bar member.

According to another embodiment, the web members are arranged repeatedly in the gap direction at a distance D over the gap height H. The web member has a slope ratio R to height of D/H.

According to one embodiment, the web member comprises:
i) angled web members arranged repeatedly with the same angle of inclination;
ii) sloped segments that result in a zigzag web pattern along the gap and have the same slope angle value but alternating slope directions;
iii) intersecting and repeating inclined web segment portions resulting in an X-shaped repeating web pattern;
is arranged at least as one of

According to one embodiment, the grating is an absorption grating for phase-contrast X-ray imaging and/or dark-field X-ray imaging.

According to another embodiment, the grid is an anti-scatter grid for X-ray imaging.

An X-ray imaging system is also provided in accordance with the present invention. An X-ray imaging system includes an X-ray source, an X-ray detector, and a grating according to one of the above embodiments arranged in a radiation X-ray path between the X-ray source and the X-ray detector. .

According to one embodiment, the X-ray source provides X-ray radiation towards the X-ray detector in an X-ray line-of-sight direction. The web member is provided obliquely with respect to the X-ray line of sight.

The term "radiation X-rays" relates to radiation X-rays produced by an X-ray source and emitted towards an X-ray detector. The term "radiation x-ray path" relates to the propagation of radiation x-rays. Therefore, the radiation x-ray path describes the spatial region to which the radiation is provided. X-ray imaging requires positioning an object along a path so that X-ray image data can be generated. A radiation x-ray path is also referred to as a "radiation x-ray beam path".

In one embodiment, the x-ray radiation is provided as a cone or fan x-ray beam. The emitted X-rays thus provide a plurality of correspondingly arranged line-of-sight directions.

In another embodiment, the emitted x-rays illuminating the object are provided as coherent emitted x-rays with the emitted x-rays arranged essentially parallel. In one example, the X-ray source provides coherent radiation. In another embodiment, the X-ray source provides non-coherent radiation. In this case, non-coherent radiation has to pass through the (source) grating structure to provide coherent radiation.

The term "x-ray line of sight" relates to the direction of emitted x-rays from the x-ray source to the x-ray detector. For cone or fan beams, the x-ray line-of-sight directions are different across the beam. In the case of coherent radiation X-rays, ie parallel radiation X-rays, the X-ray line-of-sight directions of the entire beam are parallel to each other.

In one embodiment, the grid is provided as a planar grid in which the web members are parallel to each other. When assembling the grating into an X-ray imaging system using a fan or cone beam, the grating is focused during assembly of the imaging system. For example, when attaching a grid to a corresponding molding surface, the grid is attached to the molding surface and bent. In one embodiment, the surface is curved, such as a surface having a shape from a portion of a concave sphere.

According to one embodiment, a grating arrangement for phase-contrast X-ray imaging and/or dark-field X-ray imaging is provided with an X-ray imaging system. At least partially coherent radiation x-rays are provided for illuminating an object. The grating component includes at least a phase grating and an analyzer grating. The grating is provided as an absorption grating forming an analyzer grating and/or a source grating to provide at least partially coherent emitted X-rays.

That is, in order to provide at least partially coherent X-ray radiation, the analyzer grating and/or the source grating are provided as absorption gratings, which absorption gratings are provided as gratings according to one of the above embodiments. be done.

A method of manufacturing a grid for X-ray imaging is also provided in accordance with the present invention. The method is
a) creating a grid structure having a first plurality of bar members and a second plurality of gaps;
b) creating a fixed structure positioned between the bar members to stabilize the grid bar members;
and the bar members extend lengthwise and heightwise and are separated from each other in a direction transverse to the heightwise direction by one of the gaps. The fixed structure includes a plurality of bridging web members provided between adjacent bar members. The web members are longitudinal web members extending in the direction of the gap and provided at an angle to the height direction.

Grating-based phase-contrast imaging and dark-field imaging are promising techniques for enhancing the diagnostic quality of X-ray equipment, for example in the fields of mammography, chest X-ray and CT. According to one aspect, a grating solution for clinical systems for grating-based phase-contrast imaging and darkfield imaging is provided. For example, in an absorption grating G0 (“source grating”) or an absorption grating G2 (“analyzer grating”), at heights above 200 μm, several For example, a gold grating structure with a pitch of the order of μm to several tens of μm is provided. The so-called LIGA process, for example, is used to manufacture such gratings. By directing the stabilizing structure, the grating is stabilized and the adhesion forces do not affect the geometric accuracy of the grating. By providing the slanted web members as e.g. slanted bridges, artifacts caused by fixed element structures detected by sensors are reduced. Improved signal quality is achieved by providing uniform x-ray attenuation. A further consequence of embodiments using a continuous web member is that only one mask is required in the manufacturing process. Additional unwanted interference fringes or additional noise are avoided or at least reduced.

In one embodiment, the mask with the bridge design is tilted about an axis perpendicular to the desired grating direction during the lithography step. This results in an inclined bridge or said web member. Additional attenuation due to bridges is more evenly distributed over the grating area, which reduces the impact on image quality. In one embodiment, for a given grating height H and distance d between web members along the trench, there is a dedicated tilt angle such that a uniform grating structure is achieved in transmission normal to the grating area. In one embodiment, this tilt angle α satisfies the relationship tan α=d/H. At the same time, only one exposure step is required during lithography. The maximum length of the tilted bridge structure correlates with the maximum achievable depth of the lithographic process. The tilt angle must be chosen not only according to lithographic limits, but also the ability to electroplate gold (or other material) under the bridge structure in the open parallelogram volume.

Differential phase-contrast imaging and dark-field imaging rely on the use of X-ray optical gratings. According to one aspect, web members are provided, for example as bridge structures, to mechanically stabilize the lattice structure. This structure minimizes non-uniformity without increasing lithographic complexity for fabrication. A web segment is rotated about an axis of rotation that is perpendicular to the grating direction. By doing so, a uniform grating can be obtained without increasing lithographic complexity.

Instead of tilting in the α or −α directions, it is also possible to have V- and W-shaped structures as well as X-shaped structures, for example with uniformly distributed absorption of the stabilizing structures along the entire groove, as a double exposure step. It is possible. In one embodiment, the grid comprises multiple rotated web members to obtain an X pattern, a V pattern, an XXX pattern, a VVV pattern, or a combination of XV patterns (viewed along the grid direction). include.

In one embodiment, the X-pattern, XV-pattern or VV-pattern is displaced such that there is a gap so that the bottom can be filled with, for example, an X-ray absorbing material. For example, a distance is provided to achieve a V_V pattern. Alternatively, a vertical displacement of the top edge is provided such that the gap is along the vertical direction.

In one example, filling can be provided by electroplating.

These and other aspects of the invention will become apparent from and will be explained with reference to the embodiments to be described hereinafter.

Exemplary embodiments of the invention are described below with reference to the following drawings.

FIG. 1 shows a portion of one embodiment of a grid in perspective view. FIG. 2 shows a cross-sectional view along the gap of one embodiment of the grid. FIG. 3 shows a further embodiment of the grid in cross section along the gap. FIG. 4 schematically shows one embodiment of an X-ray imaging system. FIG. 5 shows a schematic configuration of an imaging system for differential phase contrast X-ray imaging. FIG. 6 shows the steps of one embodiment of a method of manufacturing a grating.

FIG. 1 shows a grid 10 for X-ray imaging. Grating 10 includes a grating structure 12 having a first plurality of bar members 14 and a second plurality of gaps 16 . Lattice 10 further includes securing structures 18 disposed between bar members 14 to stabilize bar members 14 . Grating bars or bar members 14 extend in a length direction 20 and a height direction 22 . The bar members 14 are separated from each other by one of the gaps 16 in a direction transverse to the height direction 22, i.e. the spacing direction. The spacing direction is indicated by distance arrows 23 . The gap 16 is arranged in a gap direction 20 ′ parallel to the length direction 20 . Fixed structure 18 includes a plurality of bridging web members 24 provided between adjacent bar members 14 . Web member 24 is a longitudinal web member extending in gap direction 20 ′ and provided at an angle to height direction 22 . A slope is provided in the gap direction 20'.

FIG. 2 shows a cross-sectional view along the gap with slanted web members 24 provided slanted over the length direction 20 and height direction 22 . The tilt angle is indicated by reference number 26 .

Further, in an embodiment not shown, the web members 24 are arranged parallel to the bar members 14 and extend over the length of their sides, i.e. over the length of each web member 24 to the bar members 14 . Connected.

Further, in an embodiment not shown, web members 24 are positioned between adjacent bar members 14 such that web members 24 are connecting opposed and facing portions of bar members 14 .

That is, the web members 24 extend vertically across the width of the gap, preferably vertically, ie across the spacing direction 23 . For example, the web member 24 is fixedly attached to the opposing portion. As noted above, the web members 24 span across the gap direction in their transverse cross-sections. That is, the web members 24 connect the bar members 14 in a direction perpendicular to the gap direction and perpendicular to the depth of the gap, ie perpendicular to the line of sight direction.

In one embodiment, longitudinal web members 24 are provided as straight web members.

The bar members 14 (first plurality) and gaps 16 (second plurality) form a grid area. In one embodiment, the grid areas form grid planes. In another embodiment, the grating regions are provided in a curved manner on the cylindrical surface.

The web member 24 is arranged obliquely with respect to the main radial x-ray direction, i.e. obliquely with respect to the line of sight direction. In the radial direction perpendicular to the grid, ie the grid extension within the grid area, the web members 24 are arranged obliquely with respect to the normal of the grid area. The web members 24 are arranged at an oblique angle with respect to the grid areas or grid planes.

The web members 24 stabilize the bar members 14 of the grid structure. By providing the web members 24 at an angle, the damping provided by the web members 24 is more distributed.

A "bar member" 14 is also referred to as a bar element or bar segment.

"Web members" 24 are also referred to as web elements, web segments, bridges or bridge segments.

The web member 24 provides a stabilizing web that supports the bar member 14, ie, the bar.

Furthermore, in a non-illustrated embodiment, at least one first gap and at least one web segment are provided over the height in the viewing direction of the X-ray radiation.

In one embodiment, at least the first gap is X-ray transparent and provides no X-ray attenuation. X-ray radiation is attenuated only in the gaps where the web segments are located.

The height direction is also referred to as the first direction or first height direction, and the length direction is also referred to as the second direction or second length direction.

In one embodiment, the grating is an absorbing grating and the grating structure is made such that the bar members are made of an X-ray absorbing material for X-ray absorption by the bar members. The gap is provided with low absorption so that X-rays are transmitted within the gap. Preferably, the interstices are less X-ray absorptive than the web segments.

For example, the web members 24 are provided from the same material as the bar members. In one embodiment, web member 24 is also made from an X-ray absorbing material.

In a further embodiment the grid is an absorbing grid and the grid structure is made such that the gaps are filled with an X-ray absorbing material for X-ray absorption by the gaps. The bar member is provided with low absorption so that X-rays are transmitted within the bar member.

In another embodiment, web member 24 is also made to have low absorption so that it is transparent to X-rays.

In one embodiment, optionally shown in FIG. 3, the web member 24 is arranged to provide continuous x-ray attenuation along the gap in the line-of-sight direction 28 of the emitted x-rays. be done.

For example, the web members 24 are arranged such that, in the x-ray line-of-sight direction, the emitted x-rays pass through one web member while passing through (ie, emitted through) the gaps of the grid. In another embodiment, the radiation passes through two or three web members 24 . The number of web members 24 passed is the same throughout the gap and is also the same within the gap in the gap direction.

Providing a continuous x-ray attenuation reduces the amount of artifacts in the x-ray signal provided by the detector.

The advantage of this arrangement is the single irradiation step. However, instead of tilting in the direction of α or -α, it is also possible to have a double irradiation step, eg for V- and W-shaped structures and X-shaped structures. These can also provide uniformly distributed absorption of the stabilizing structure along the entire groove.

In another embodiment, the web members are provided to extend perpendicular to the gap direction. Several web members are provided over the height of the gap, which are displaced in the direction of the gap. In one embodiment, the same degree of x-ray attenuation is provided along the gap in the line-of-sight projection.

As an option shown in FIG. 3, web member 24 extends continuously from upper edge 30 of bar member 14 to lower edge 32 of bar member 14 .

As a result, only one mask is required for the manufacturing process and only one exposure is required in the lithography step. However, this also results in a uniformity being created within the grating that prevents additional unwanted interference fringes from being created. Uniformity is provided especially when the web members 24 are regularly distributed.

Additional attenuation by web member 24 is more evenly distributed over the grating area, which reduces the impact on image quality.

As a further option, not shown in detail, the web member 24 is arranged as at least one of the following:
i) repeated inclined web members with the same inclination angle; and ii) inclined segments with the same inclination angle value but alternating inclination directions. This results in a zigzag web pattern along the gap.
iii) repeating slanted web segment portions provided to intersect; This results in an X-shaped repeating web pattern.

In one embodiment, the zigzag pattern includes portions along only a fraction of the height of the gap that extend that height but have the same slope. This still results in an even distribution of attenuation.

FIG. 3 shows a pattern of repeating angled web members 24 . The web members 24 are repeatedly arranged over the gap height H at distances D in the gap direction. The web member 24 has a slope ratio R of D/H with respect to the height direction. Distance D is also called pitch. In one embodiment, for a given grating height H and distance D between bridges along the trench, there is a dedicated tilt angle such that a uniform grating structure is achieved in transmission normal to the grating area. . This tilt angle α satisfies the relationship tan α=D/H, as shown in the option of FIG.

In one embodiment, the grating is an absorption grating for phase-contrast X-ray imaging and/or darkfield X-ray imaging.

The fixed structure addresses the production of gratings in phase-contrast X-ray imaging, in particular absorption gratings G0 (as source grating following the X-ray source) and absorption gratings G2 (as analyzer grating before the detector). For example, in order to achieve sufficient attenuation over the entire spectrum of an X-ray tube, grating structures with pitches on the order of a few microns to a few tens of microns are provided at gold heights above 200 μm. Processes including lithography, electroplating and molding can be applied to make such gratings. This process is known as the LIGA process (German for Lithographie, Galvanoformung, Abformung). The anchoring structure stabilizes the grid, which otherwise tends to be unstable due to adhesion forces, especially for high aspect ratios.

In another option, the grid is an anti-scatter grid for X-ray imaging.

FIG. 4 schematically shows an x-ray imaging system 50 including an x-ray source 52 and an x-ray detector 54 . Additionally, grid 56 is provided as an example of one of the grids described above. A grating 56 is provided to be positioned in the emitted x-ray path 58 between the x-ray source 52 and the x-ray detector 54 .

FIG. 5 shows a system 50' for phase-contrast X-ray imaging and/or dark-field X-ray imaging as an option for the X-ray imaging system. A grating arrangement 60 is provided for phase-contrast X-ray imaging and/or dark-field X-ray imaging. At least partially coherent radiation X-rays 61 are provided to illuminate an object 62 . The grating configuration section 60 includes at least a phase grating G1 and an analyzer grating G2. Optionally, a source grating G0 may also be provided for providing said at least partially coherent X-ray radiation. The analyzer grating G2 and/or the source grating G0 are provided as absorption gratings provided as gratings according to one of the above embodiments. Further aspects such as phase stepping for differential phase contrast imaging are not described in further detail.

FIG. 6 shows one embodiment of a method 100 for manufacturing a grating for X-ray imaging. Method 100 includes the following steps. In a first step 102, also referred to as step a), a grid structure having a first plurality of bar members and a second plurality of gaps is produced. The bar members extend lengthwise and heightwise and are separated from each other in a direction transverse to the heightwise direction by one of the gaps. In a second step 104, a fixed structure is created to be placed between the bar members to stabilize the grid bar members. The fixed structure includes a plurality of bridging web members provided between adjacent bar members. The web member 24 is a longitudinal web member extending in the direction of the gap and provided at an angle to the height direction.

In one embodiment, steps a) and b) are performed simultaneously. In another embodiment, steps a) and b) are performed in sequence with each other.

Furthermore, in one embodiment, not shown, in step a1) a mask for the radiation source is provided for shielding the radiation in the structure provided as a grid structure with a first plurality of bar members and a second plurality of gaps. A fixing structure is provided between the bar members for stabilizing the bar members of the grid. The bar members extend lengthwise and heightwise and are separated from each other by one of the gaps transversely to the heightwise direction. The fixed structure includes a plurality of bridging web members 24 provided between adjacent bar members. The web member 24 is a longitudinal web member extending obliquely with respect to the height direction. In step a2) a radiation sensitive photoresist material is provided. In step b'), the photoresist material is irradiated with radiation while shielding the photoresist material with a mask, so that part of the photoresist material is fixed and other parts are not fixed. In step c) the unfixed parts of the photoresist material are removed while keeping the fixed parts as a mold. In step d) a grating structure is galvanically generated in the removed part. In step e) the fixed part is removed.

Irradiation and curing of photosensitive substances are also called lithographic processes.

For example, galvanic generation of grids is provided by electroplating.

In one embodiment, the radiation used to irradiate the photoresist material is low energy X-rays (eg, 5-10 keV) from a synchrotron radiation source.

In another embodiment, the radiation used to irradiate the photoresist material is light from an ultraviolet light source.

The advantage of this shape of grating is the single irradiation step (see below). However, instead of tilting in the direction α or −α, it is also possible to have a double exposure step, eg for V- and W-shaped structures and X-shaped structures (see above). These can also provide uniformly distributed absorption of the stabilizing structure along the entire groove.

In one embodiment, in only one irradiation step b), only one mask is provided in step a).

In one embodiment, the mask has a bridge design and the mask tilts about an axis perpendicular to the desired grating direction. The slanted bridges thereby form the web members 24 described above.

The maximum structural length of the angled web member 24 correlates to the maximum achievable depth of the lithographic process. In one embodiment, the tilt angle is selected not only according to lithography limits, but also the ability to electroplate gold (or other material) under the structure of web member 24 within the open parallelogram volume. be.

It is noted that embodiments of the invention are described with reference to various subject matter. In particular, some embodiments are described with reference to method-type claims, while other embodiments are described with reference to device-type claims. However, a person skilled in the art will understand from the above and following description that, unless otherwise stated, any combination of features belonging to one type of subject matter as well as any combination of features relating to various subject matter also applies to the present application. It will be understood that it is considered to be disclosed by. However, all features can be combined so long as they provide a synergistic effect beyond the mere addition of the features.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative and not restrictive. The invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments will be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the dependent claims.

In the claims, the term "comprising" does not exclude other elements or steps, nor does the indefinite article "a" or "an" exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope.

Claims (13)

a lattice structure having a plurality of bar members and a plurality of gaps;
a securing structure disposed between said bar members for stabilizing said bar members;
An X-ray imaging grid comprising:
The bar members extend in a length direction and a height direction and are separated from each other in a direction transverse to the height direction by one of the gaps, the gap being in a gap direction parallel to the length direction. is placed in
said anchoring structure comprising a plurality of bridging web members provided between adjacent bar members;
the web member is a longitudinal web member extending in the gap direction and inclined with respect to the height direction, the inclination being provided in the gap direction;
The lattice is
i) absorption gratings for phase-contrast X-ray imaging and/or dark-field X-ray imaging, or
ii) an anti-scatter grid for X-ray imaging,
A grating for X-ray imaging wherein said web members are arranged to provide continuous X-ray attenuation along said gaps in a radial X-ray line-of-sight direction. 2. The grid of claim 1, wherein said web members and said bar members are made from the same material and said web members and said bar members are made as a unitary structure. a lattice structure having a plurality of bar members and a plurality of gaps;
a securing structure disposed between said bar members for stabilizing said bar members;
An X-ray imaging grid comprising:
The bar members extend in a length direction and a height direction and are separated from each other in a direction transverse to the height direction by one of the gaps, the gap being in a gap direction parallel to the length direction. is placed in
said anchoring structure comprising a plurality of bridging web members provided between adjacent bar members;
the web member is a longitudinal web member extending in the gap direction and inclined with respect to the height direction, the inclination being provided in the gap direction;
The lattice is
i) absorption gratings for phase-contrast X-ray imaging and/or dark-field X-ray imaging, or
ii) an anti-scatter grid for X-ray imaging,
an X- ray absorbing material for X-ray absorption disposed within said gap, said bar member and said web member being made of a material having less X-ray absorption than said X-ray absorbing material; lattice. wherein the grid is an absorbing grid and the grid structure is made such that the interstices are filled with the X-ray absorbing material for X-ray absorption by the interstices;
4. The grid of claim 3, wherein the bar members are arranged to have low x-ray absorption for radiation x-ray transmission within the bar members. The grating is an absorbing grating, and for X-ray absorption by the bar members, the grating structure is made such that the bar members are made of an X-ray absorbing material, and the gaps are such that radiation in the gaps is 3. A grating according to claim 1 or 2, for X-ray transmission, arranged to have low X-ray absorption. 6. A grid according to any one of the preceding claims, wherein the web members are arranged between adjacent bar members such that the web members connect opposing portions of the bar members. 7. The grating according to any one of the preceding claims, wherein in the X-ray viewing direction, over its height, at least one first gap and at least one web member are provided. The web member extends continuously from an upper edge of the bar member to a lower edge of the bar member; and/or
8. The web members of any of claims 1 to 7, wherein the web members are repeatedly arranged in the gap direction at a distance D over the gap height H, and wherein the web members have a slope ratio R to the gap height direction of D/H. or the grid according to item 1. The web member
i) angled web members arranged repeatedly with the same angle of inclination;
ii) sloping segments resulting in a zigzag web pattern along said gap, having the same slope angle value but alternating slope directions;
iii) repeated intersecting slanted web segment portions resulting in an X-shaped repeating web pattern;
9. A grating according to any one of claims 1 to 8, arranged at least as one of an x-ray source;
an X-ray detector;
a grating according to any one of claims 1 to 9, arranged in the radiation X-ray path between the X-ray source and the X-ray detector;
An X-ray imaging system, comprising: said x-ray source providing said radiation x-rays towards said x-ray detector in an x-ray line-of-sight direction;
11. The X-ray imaging system of claim 10, wherein said web member is provided obliquely with respect to said X-ray line-of-sight direction. a grating arrangement for phase-contrast X-ray imaging and/or dark-field X-ray imaging;
at least partially coherent radiation x-rays are provided to illuminate an object;
the grating component includes at least a phase grating and an analyzer grating;
The lattice is
the analyzer grid and/or
12. An X-ray imaging system according to claim 10 or 11, provided as an absorption grating forming a source grating for providing said at least partially coherent X-ray radiation. a) creating a grid structure having a plurality of bar members and a plurality of gaps;
b) creating a fixation structure to be arranged between said bar members to stabilize said bar members;
1. A method of manufacturing a grating for radiographic imaging comprising:
said bar members extend in a length direction and a height direction and are separated from each other by one of said gaps in a direction transverse to said height direction;
The fixing structure includes a plurality of bridging web members provided between adjacent bar members, the bridging web members extending in the direction of the gap and provided at an angle with respect to the height direction. a longitudinal web member;
A method of manufacturing a grating for X-ray imaging, wherein said bridging web members are arranged to provide a continuous degree of X-ray attenuation along said gaps in a radial X-ray line-of-sight direction.

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